300年来鄱阳湖营养盐演化重建与模拟  

Reconstructions and simulations of nutrient evolution in Poyang Lake over the past 300 years

作　　者：廖梦娜[1,2] 于革[1,2] 郭娅[1,2] 

机构地区：[1]中国科学院南京地理与湖泊研究所,南京210008 [2]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京210008

出　　处：《生态学报》2016年第8期2393-2402,共10页Acta Ecologica Sinica

基　　金：科技部全球变化重大科学研究计划项目(2012CB956103;2013CB956501);中国科学院国际合作创新团队项目(KZZD-EW-TZ-08)

摘　　要：水体富营养化已经成为全球性的问题而受到广泛关注,然而其发生的过程和机制尚未完全明了。在湖泊营养演化过程中,水文和生态是两个最基本的制约因素。相对于短期的和试验性的研究,长时间尺度的营养盐变化过程能更全面地揭示营养盐的演化机制。以我国最大的淡水湖——鄱阳湖为例,采用湖泊水体交换周期模型和湖泊生态-营养盐动力耦合模型,重建鄱阳湖营养盐的长期变化,并利用沉积钻孔代用指标加以验证。在此基础上探讨其演化机制,模拟的时间序列中营养盐变化对气候水文与生态系统存在两种不同的响应模式。敏感因子分析显示:典型同步响应期中(1812—1828 AD),气候水文因子的贡献率达79.1%,生态因子为20.9%;典型异步响应期中(1844—1860 AD),两者贡献率分别为36.4%和63.6%。在模拟的营养盐变化时间序列中同步期占62.5%,说明气候因子在营养盐演化过程中起重要的作用;异步期虽只占12.5%,但对湖泊营养盐作用、营养盐反馈生物量同样至关重要。相关分析结果显示,生物量增长与TP含量基本呈线性关系,但存在一个阈值。在没有超过阈值前,生物量对TP具有较好的调节作用;当超过阈值之后,生物量的调节作用减弱。Lake eutrophication has become a global environmental problem and severely affects water resource quality. Although studies have addressed eutrophication, the mechanisms are not fully understood to date because of the water- biomass-sediment complexity in lakes, and limited observation data makes analysis of the entire nutrient evolution process difficult. Therefore, to reveal eutrophication mechanisms more comprehensively, analysis should be based on long-term processes of nutrient changes. In lake ecosystems, all stresses and forces interact during the eutrophication, among which, hydrology and ecosystem play key roles. Hydraulic residence time impacted nutrient supply, lake productivity, and nutrient accumulation processes profoundly. With water cycles and energy exchanges in lake ecosystems, primary productivity is a critical process contributing to lake trophic states. southern bank of the middle-reach of the Yangtze quality of Poyang Lake was mesotrophic during the the 21th century. To discern the trophic evolution dynamic models, were used in the present study Poyang Lake, the largest fresh water lake in China, is located on the River. Compared with most other eutrophic lakes in the region, water 20th century. However, water quality has declined since the beginning of of Poyang Lake, hydraulic residence time and lake ecosystem-nutrient to determine long-term changes of nutrients and biomass in the lake.Furthermore, sediment records, including total organic carbon （TOC）, Pollen concentration and DI-TP series derived by using diatom-TP transfer function, compared the simulation results of the past 300 years. The simulation revealed that nutrient TP changed differentially in response to changes in climatic-hydrological and climatic-ecosystem conditions. Control runs for 1955--2008 proved that TP increase was consistent with the observed growth of primary producer biomass. On this basis, we ran the models for a long-term period from 1700 to 1899. The time-series analysis for the simulations showed that the

关 键 词：:营养盐演化 水体交换周期 湖泊生态-营养盐动力模型 贡献率 鄱阳湖 

分 类 号：X524[环境科学与工程—环境工程]